The present invention relates to a device and a method for laying rigid tubular pipes on the seabed using a laying vessel.
More specifically, this device is designed for so-called J-lay methods, which make it possible to install the pipe without plastic deformation.
It is known for devices such as this intended for laying underwater pipes to include a tower which can be inclined on a working platform and in which a moon pool is provided for example, and means for holding and translationally driving pipe sections, which sections are assembled sequentially to form the pipe which is then submerged.
The pipe sections, which are preassembled on the vessel or on land, are brought sequentially to the said tower and are held by retaining means which for their part are mounted so that they can move translationally up and down the tower. Lower retaining means are mounted in the lower part of the tower and they are designed to hold a free end of the pipe submerged, while upper retaining means are intended to retain a pipe section to be connected.
These retaining means comprise clamping jaws which grip around the outer wall of the pipe sections so as to prevent them from moving translationally. Reference may be made particularly to document WO 99/35429, which describes such retaining means.
However, these clamping jaws necessarily compress the pipes and run the risk of damaging them. This probability is all the likelier in the case of pipes having an outer covering, for example a thermal insulation layer or even an anticorrosion covering.
A problem which arises and which the present invention aims to solve is thus that of providing a device and a method which make it possible to install underwater pipes without damaging them.